One day, a disgruntled employee stole the signing key. Now, anyone with that key could sign any malicious image, and Fastboot Secure Boot would happily accept it—because it trusted the signature, not the intent.

But a new problem emerged:

Fastboot Secure Boot had won this battle. Today, every Android device sold globally uses Fastboot Secure Boot (often merged into the broader Android Verified Boot ). It protects billions of devices from low-level malware.

fastboot flash boot malware.img The device replied: